Albert Einstein postulated in his 1905 theory of special relativity that the speed of light in a vacuum is constant. Ever ...

In 1971, graduate student Stuart Freedman and postdoctoral fellow John Clauser took over a room in the sub-basement of Birge Hall at the University of California, Berkeley, and built an experiment ...

To learn more about the nature of matter, energy, space, and time, physicists smash high-energy particles together in large accelerator machines, creating sprays of millions of particles per second of ...

When a star dies, it generates an explosion of elemental nuclei and hurls them into space. Those elements, called cosmic rays ...